Need advice on flaky A1200

Ledfoot · 05 November 2018, 02:57

Hey gang...

Bought an A1200 last month, but it didn't come with a PSU or video cable, so I had no way to test it until today. Rev 1B board.

Finally got access to a PSU for a few hours today from a friend so I could try out my A1200. Recently had it recapped using the kit from Amikit by a friend's company that does circuit work, so it was professionally done. They did have an issue as the kit was missing a cap for C460 (think that was the number he said... the second from the right in the front row of the small ones just above the PCMCIA port).

Anyhow, I installed the 3.1 ROMS I bought, went to power on and one time it would work, the next time it wouldn't. Sometimes I'd get a RED screen, other times White, other times it would boot the CF properly. Went back to the 3.0 ROMS and started having similar issues.

We tried doing very systematic build ups - strip it down to bare stock - no accel board, no IDE/CF, no floppy, no RapidRoad, original roms, no external floppy, no keyboard, no mouse - just power and video... Ok that works... Then we'd add the mouse, ok, add the IDE, sometimes it would work, sometimes not. Add the Blizzard 1230 might work, and so on...

What we eventually came to believe is that every time I press down on the board to push in the IDE, clockport, floppy or the ROMS (anything where you're applying a little force down on the MB), that's when it stops working... If I'm VERY gingerly with those, it seems to work ok.

I'm leaning towards 1 of 2 possibilities:

1) bad solder joint somewhere that flexes when I push on the board to install stuff
2) the plastic sheet that separates the MB and the lower shielding is being punctured sometimes when the board is pressed on. Maybe a little solder point from the new through-hole Caps?

I'm also getting VERY wavy video signal (although that's hard to know for sure because we only had a very poor RGB-CGA-VGA adaptor unit to hook it up to a monitor. (I'm waiting on a SCART cable for SCART-HDMI adaptor.)

Any other ideas of things that could be the cause? I've triple verified the ROMS are in properly, no pins are broken or bent, etc. At this point I'm back on the 3.0 ROMS...

Also, where/how do folks usually mount the rapid road unit? (it's REALLY annoying that the clockport cable seems to need to flip over to install it...) I picked up some double sided foam tape but not sure if that's a good idea or not.

I just ordered the PicoPSU adapter board so hopefully I'll have a working PSU of my own in a week or two so I can do more troubleshooting and get things working better.

Vypr · 05 November 2018, 10:13

Well, a solid red screen indicates an error reading the ROM, it is possible there is a bad solder joint on one of the sockets, maybe you could ask your friends company if they can reflow the solder or even replace the sockets?
On option 2 you're more likely to get a short and see a lot of smoke coming out, I have a board with a burned track because of a punctured insulation sheet. If you're worried about that, Amigakit sells replacement insulation sheets.
regarding the RapidRoad, IIRC, the Rev 1B board has a full row of pins on the clockport while later revisions only had half the pins populated so this is probably why you are having problems plugging the RapidRoad in.

Ledfoot · 05 November 2018, 22:14

Yeah, I'm betting when I pushed in the Roms the board flexed enough to crack an old solder joint, or it happened when I was removing 2 of the clockport pins for (the ones on the left unused portion of the cLockport) to support installation of the Rapid Road's cable. When I was bending those 2 pins back and forth to get them to stress snap I heard a good amount of creaking from the board so it's possible it's there as well...

We do have a hot air reflow portion on our soldering station at work, so I might be able to bring it in there this weekend and at least try hitting those pins on the back quickly and see if that helps at all. I should get the PicoPSU power adaptor board from Ian Stedman in a week or so, so then I'll be able to spend more time troubleshooting when I can actually power the board up and test it as I go.

Ledfoot · 06 November 2018, 20:35

Also, it's not that I'm having a problem plugging the Rapid Road in - I removed 2 of the unused pins off the clockport header so the cable can plug in. I'm asking where people typically mount the RR board inside their case. Over the Chip RAM??? How do they mount it?

05 November 2018, 02:57	#1
Ledfoot Registered User Join Date: Oct 2018 Location: Cherry Hill, NJ USA Posts: 85	Need advice on flaky A1200 Hey gang... Bought an A1200 last month, but it didn't come with a PSU or video cable, so I had no way to test it until today. Rev 1B board. Finally got access to a PSU for a few hours today from a friend so I could try out my A1200. Recently had it recapped using the kit from Amikit by a friend's company that does circuit work, so it was professionally done. They did have an issue as the kit was missing a cap for C460 (think that was the number he said... the second from the right in the front row of the small ones just above the PCMCIA port). Anyhow, I installed the 3.1 ROMS I bought, went to power on and one time it would work, the next time it wouldn't. Sometimes I'd get a RED screen, other times White, other times it would boot the CF properly. Went back to the 3.0 ROMS and started having similar issues. We tried doing very systematic build ups - strip it down to bare stock - no accel board, no IDE/CF, no floppy, no RapidRoad, original roms, no external floppy, no keyboard, no mouse - just power and video... Ok that works... Then we'd add the mouse, ok, add the IDE, sometimes it would work, sometimes not. Add the Blizzard 1230 might work, and so on... What we eventually came to believe is that every time I press down on the board to push in the IDE, clockport, floppy or the ROMS (anything where you're applying a little force down on the MB), that's when it stops working... If I'm VERY gingerly with those, it seems to work ok. I'm leaning towards 1 of 2 possibilities: 1) bad solder joint somewhere that flexes when I push on the board to install stuff 2) the plastic sheet that separates the MB and the lower shielding is being punctured sometimes when the board is pressed on. Maybe a little solder point from the new through-hole Caps? I'm also getting VERY wavy video signal (although that's hard to know for sure because we only had a very poor RGB-CGA-VGA adaptor unit to hook it up to a monitor. (I'm waiting on a SCART cable for SCART-HDMI adaptor.) Any other ideas of things that could be the cause? I've triple verified the ROMS are in properly, no pins are broken or bent, etc. At this point I'm back on the 3.0 ROMS... Also, where/how do folks usually mount the rapid road unit? (it's REALLY annoying that the clockport cable seems to need to flip over to install it...) I picked up some double sided foam tape but not sure if that's a good idea or not. I just ordered the PicoPSU adapter board so hopefully I'll have a working PSU of my own in a week or two so I can do more troubleshooting and get things working better.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
New to A1200 advice	richfr	New to Emulation or Amiga scene	10	25 October 2018 19:04
Amiga 2000 with Flaky Controller Ports: Help Needed	DocFlareon	support.Hardware	6	31 January 2018 18:42
Two Isses with A1200 - advice please	Havie	support.Hardware	4	24 February 2014 08:10
Some A1200 Advice	amiga1	support.Hardware	2	26 September 2011 18:48
flaky A500 PSU on A1200	Dave_wb	support.Hardware	1	13 September 2007 12:39

05 November 2018, 10:13	#2
Vypr Registered User Join Date: Dec 2016 Location: East Kilbride, Scotland Posts: 452	Well, a solid red screen indicates an error reading the ROM, it is possible there is a bad solder joint on one of the sockets, maybe you could ask your friends company if they can reflow the solder or even replace the sockets? On option 2 you're more likely to get a short and see a lot of smoke coming out, I have a board with a burned track because of a punctured insulation sheet. If you're worried about that, Amigakit sells replacement insulation sheets. regarding the RapidRoad, IIRC, the Rev 1B board has a full row of pins on the clockport while later revisions only had half the pins populated so this is probably why you are having problems plugging the RapidRoad in.

05 November 2018, 22:14	#3
Ledfoot Registered User Join Date: Oct 2018 Location: Cherry Hill, NJ USA Posts: 85	Yeah, I'm betting when I pushed in the Roms the board flexed enough to crack an old solder joint, or it happened when I was removing 2 of the clockport pins for (the ones on the left unused portion of the cLockport) to support installation of the Rapid Road's cable. When I was bending those 2 pins back and forth to get them to stress snap I heard a good amount of creaking from the board so it's possible it's there as well... We do have a hot air reflow portion on our soldering station at work, so I might be able to bring it in there this weekend and at least try hitting those pins on the back quickly and see if that helps at all. I should get the PicoPSU power adaptor board from Ian Stedman in a week or so, so then I'll be able to spend more time troubleshooting when I can actually power the board up and test it as I go.

06 November 2018, 20:35	#4
Ledfoot Registered User Join Date: Oct 2018 Location: Cherry Hill, NJ USA Posts: 85	Also, it's not that I'm having a problem plugging the Rapid Road in - I removed 2 of the unused pins off the clockport header so the cable can plug in. I'm asking where people typically mount the RR board inside their case. Over the Chip RAM??? How do they mount it?

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)